Sensor arrangement for a construction machine

ABSTRACT

The invention relates to a sensor arrangement for a construction machine with a sensor which is set up for gathering measurement data from a sampling region or from a sampling point. The invention is characterised in that an illumination device for illuminating the sampling region or the sampling point is integrated into the sensor arrangement.

The invention relates to a sensor arrangement for a construction machinewhich is set up to gather measurement data from a sampling region orfrom a sampling point.

Sensor arrangements of this nature for construction machines, such asfor example pavement laying machines, are known from practice. Themeasurement data gathered therefrom are used to inspect the workingresult of the construction machine, in particular the quality of thisworking result, and to set the operating parameters of the constructionmachine according to the measurement data in order to achieve the bestpossible working result.

A disadvantage of the conventional sensor arrangements is that they aresubjected to very high levels of stress and soiling due to the workingenvironment of the construction machine. This can result in themeasurement data supplied by a sensor in the sensor arrangement beingunreliable. Due to the unreliable, erroneous measurement data, theoperation of the construction machine can be impaired and the workingresult achieved may be further degraded if the operating parameters ofthe construction machine are incorrectly set on account of theunreliable measurement data.

The object of the present invention is to make a sensor arrangementavailable, which facilitates a more reliable operation of theconstruction machine with the most constructively simple means.

The object is solved by a sensor arrangement that is set up to gathermeasurement data from a sampling region or a sampling point, and havingan illumination device for illuminating the sampling region or thesampling point integrated into the sensor arrangement. Advantageousfurther developments of the invention are given in the dependent claims.

The sensor arrangement according to the invention is characterised inthat an illumination device for illuminating the sampling region or thesampling point of the sensor is integrated into the sensor arrangement.This offers a whole range of advantages. Due to the illumination of thesampling region or the sampling point from which the sensor gathersmeasurement data, the contrast is increased here such that themeasurement data are more accurate. Even when the construction machineis operated at night or in a building structure or tunnel, i.e. in thedark, the illumination enables an operator of the construction machineto check the quality and the surface condition of the sampling region orthe sampling point. In this way he can visually inspect the quality ofthe working result and whether the sampling region or sampling point(combined in the following as the sampling field) is sufficiently cleanso that reliable measurement data can be expected from the sensor. It isalso advantageous in that, due to the integration of the illuminationdevice into the sensor arrangement, cabling to an external illuminationdevice can be avoided, and that the quality of the illumination isindependent of whether and optionally in which form externalillumination elements are present on the construction site (for example,on masts). Furthermore, it is no longer necessary to align an existingworking light on the construction machine to the sampling field in orderto inspect the quality of this sampling field, so that the working lightcan be used for its designated purpose of illuminating the working areaof the construction machine.

The sensor present in the sensor arrangement may be, for example, amechanical sensor or a non-contacting sensor. It is also within thescope of the present invention to have a plurality of sensors present inthe sensor arrangement and that these sensors evaluate a common samplingfield or different sampling fields.

For example, the sensor may be an optical sensor, or a non-opticalsensor, such as e.g. an inductive sensor, a capacitive sensor or anultrasonic sensor. Even with non-optical sensors of this nature theillumination device provided according to the invention is advantageousin order to be able to visually inspect the surface quality and thelevel of soiling of the sampling field. However, it is conceivable thata light or shadow pattern in the sampling field achieved by means of theillumination device is detected by means of the sensor and is used togather measurement data. For this purpose the illumination device mightproduce a structured light pattern, for example, a line or grid.Depending on the position and/or the deformation of this light patternconclusions regarding the properties of the sampling field and thusregarding the quality of the working result of the construction machinemight be obtained.

The illumination device could be formed for emitting visible and/orinfrared light. Visible light has the advantage that it facilitates avisual check of the sampling field by the operator of the constructionmachine.

It is expedient if the illumination device has an optical system fordefining and optionally for modifying the region illuminated by theillumination device. This illumination device may contain reflectorsand/or optical lenses and in this way define where the illuminatedregion lies and which dimensions it has.

It is particularly favourable if the optical system is adjustable inorder to modify the position and / or the size of the region illuminatedby the illumination device. In this way the illuminated region can beadapted to the changing operating conditions, for example to a changingdistance between the sensor and the sampling field.

In a further advantageous variant of the invention the brightness of theillumination device is variable to facilitate an optimum illumination ofthe working field with simultaneously the lowest possible energyconsumption.

It is conceivable that the sensor does not gather measurement datacontinuously, but rather that it is set up for discontinuous gatheringof measurement data, for example, according to fixed or variablemeasurement intervals. In this case it is advantageous if theillumination device is set up such that it only emits light while thesensor gathers measurement data, so that energy can be saved during theinactive state of the sensor.

In a further variant of the invention the sensor arrangement has acamera aligned on the sampling field. By means of this camera theoperator can visually inspect the sampling field illuminated by theillumination device without having to move to the sampling field.

It can also be expedient if the illumination device can be activatedindependently of the sensor operation. In this case the illuminationdevice can be switched on, for example, to visually check the samplingfield without the sensor having to be switched on as well.

The invention also relates to a construction machine, for example a roadfinisher or a charging machine, with a sensor arrangement of the abovedescribed type.

In the following an advantageous embodiment of the invention isexplained in more detail based on a drawing.

FIG. 1 shows a perspective view of an embodiment of a constructionmachine 1 with a sensor arrangement 2 according to the invention. Theconstruction machine 1 may be a road finisher or a charging machine fora road finisher. However, it may also be another construction machinewhich can be employed in darkness or in dark spaces, for example in atunnel, or in areas which are darkened inside, from which howevermeasurement data is to be gathered.

In the illustrated embodiment the sensor arrangement 2 is mounted on acomponent 4 of the construction machine 1 by means of an extension arm3, for example on an outer or inner wall 4 of the construction machine1. Alternatively, it is also conceivable that the sensor arrangement 2is integrated into the component 4 of the construction machine 1.

It is schematically indicated that the sensor arrangement 2 has a sensor5 which is set up to gather measurement data from a sampling region 6.The sampling or acquisition angle of the sensor 5 is indicated by thebroken lines 7.

The sensor 5 may be a mechanical sensor or a non-contacting sensor. Forexample, it is an ultrasonic material sensor on a screw conveyor of theconstruction machine 1, an ultrasonic level sensor or a mechanicallong-range probe. The measurement data gathered by the sensor 5 are usedto represent a state on or in the construction machine 1 or a workingresult achieved by means of the construction machine 1.

According to the invention an illumination device 8 is integrated intothe sensor arrangement 2. The illumination device 8 comprises a lightsource 9 for producing, for example, visible light. The light source 9may be an LED or an array of LEDs. Furthermore, the illumination device8 has an optical system 10 arranged in front of the light source 9. Thisoptical system 10 can comprise reflectors and/or lenses. It is used toform the light produced by the light source 9 into a conical beam 11.

Here, where the conical beam 11 from the illumination device 8 meets anotherwise dark working surface 12 an illuminated region 13 is created bythe illumination. In the present embodiment the optical system of theillumination device 8 is set such that the illuminated region 13 exactlymatches the sampling region 6 of the sensor 5. The light source 9 andthe optical system 10 can be controlled preferably by means of acontroller such that the brightness of the conical beam 11 and thedivergence of this conical beam 11 can be varied so that theillumination can adapt, for example, to a varying distance between thesensor arrangement 2 and the working surface 12.

In the operation of the construction machine 1 the illumination device 8can illuminate the region 13 on the working surface 12 when the sensor 5is active and is acquiring measurement data or when the illuminationdevice 8 has been activated independently of the operation of the sensor5 by an operator of the construction machine 1.

Starting from the illustrated embodiment, the sensor arrangement 2according to the invention can be modified in many ways. For example itwould be possible to integrate a plurality of sensors 5 into the sensordevice 2. Furthermore, a camera could be provided in the sensorarrangement 2, by means of which the region 13 illuminated by theillumination device 8 is acquired. The picture supplied by the cameracould be displayed on a display device for the operator of theconstruction machine 1.

1. Sensor arrangement for a construction machine comprising a sensor setup to gather measurement data from a sampling region or a samplingpoint, and an illumination device integrated into the sensor arrangementfor illuminating the sampling region or the sampling point.
 2. Sensorarrangement according to claim 1, wherein the sensor is a mechanicalsensor or a non-contacting sensor.
 3. Sensor arrangement according toclaim 1, wherein the sensor is an optical sensor, an inductive sensor, acapacitive sensor or an ultrasonic sensor.
 4. Sensor arrangementaccording to claim 1, wherein the illumination device is adapted foremitting visible and/or infrared light.
 5. Sensor arrangement accordingto claim 1, wherein the illumination device includes an optical systemfor defining the region illuminated by the illumination device. 6.Sensor arrangement according to claim 5, wherein the optical system canbe set to vary the position and/or the size of the region illuminated bythe illumination device.
 7. Sensor arrangement according to claim 1wherein the brightness of the illumination device is variable.
 8. Sensorarrangement according to claim 5, wherein the sensor is arranged for thediscontinuous gathering of measurement data and the illumination deviceis emits light only during the gathering of measurement data by thesensor.
 9. Sensor arrangement according to claim 1, wherein the sensorarrangement has a camera aligned with the sampling region or thesampling point.
 10. Sensor arrangement according to claim 1, wherein theillumination device can be activated independently of the operation ofthe sensor.
 11. Construction machine comprising the sensor arrangementaccording to claim
 1. 12. Construction machine according to claim 11,wherein the construction machine is a road finisher or a chargingmachine.
 13. A device for collecting data comprising a sensor positionedto gather measurement data from a sampling region or a sampling point,an illumination device integrated into the sensor device forilluminating the sampling region or the sampling point, an arm affixedto the sensor for mounting the sensor on a construction machine.
 14. Thesensor device of claim 13, wherein the sensor comprises an opticalsensor.
 15. The sensor device of claim 14, further comprising a camerapositioned to capture an image of the area illuminated by theillumination device.
 16. The sensor arrangement of claim 1, where thesensor is a non-optical sensor.
 17. The device of claim 13, wherein thesensor is a non-optical sensor.